21605617710 has 48 divisors (see below), whose sum is σ = 57986697600. Its totient is φ = 5575642560.

The previous prime is 21605617703. The next prime is 21605617721. The reversal of 21605617710 is 1771650612.

21605617710 is a `hidden beast` number, since 2 + 16 + 0 + 561 + 77 + 10 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3869185 + ... + 3874764.

It is an arithmetic number, because the mean of its divisors is an integer number (1208056200).

Almost surely, 2^21605617710 is an apocalyptic number.

21605617710 is an abundant number, since it is smaller than the sum of its proper divisors (36381079890).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21605617710 is a wasteful number, since it uses less digits than its factorization.

21605617710 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7743993 (or 7743990 counting only the distinct ones).

The product of its (nonzero) digits is 17640, while the sum is 36.

The spelling of 21605617710 in words is "twenty-one billion, six hundred five million, six hundred seventeen thousand, seven hundred ten".